diff --git a/ems-core/src/main/resources/rules/check_cond.drl b/ems-core/src/main/resources/rules/check_cond.drl
index 191cd22122..ddbe99a7d3 100644
--- a/ems-core/src/main/resources/rules/check_cond.drl
+++ b/ems-core/src/main/resources/rules/check_cond.drl
@@ -338,7 +338,7 @@ rule "checkDeleteMtbColrWithoutDoc"
 no-loop
 when
 	eval(checkRulesEnabled)
-	$entity : MtbColr(operation == OperationType.DELETE && !hasDocument || !hasQuantity)
+	$entity : MtbColr(operation == OperationType.DELETE && (!hasDocument || !hasQuantity))
 then
     PackagesRules.checkForAnyColloRif(conn, $entity.getGestione(), $entity.getSerCollo(), $entity.getNumCollo(), $entity.getDataCollo());
 end